1. Field of the Invention
The present invention relates to a liquid discharge head and a liquid discharge apparatus using the liquid discharge head.
2. Description of the Related Art
An ink jet printer (ink jet recording apparatus) is now being widely used as a liquid discharge apparatus. An ink jet head is used as a liquid discharge head in that printer. That ink jet head is based on various types of liquid discharge principles. The widespread type used in particular is an ink jet head applying thermal energy to ink to discharge ink drops from a discharge port. That type of ink jet head is advantageous in that responsiveness to record signals is good and enhancement in high density of the discharge port on a multilevel basis is easy.
However, in an ink jet printer (ink jet recording apparatus) with such an ink jet head, foreign material occasionally blocks the discharge port or bubbles mixed into inside the ink supply route occasionally blocks the ink supply route thereof. An occurrence of such events will result in ink discharge defects of an ink jet head. In particular, a so-called full-line type recording apparatus provided with a great number of discharge ports being arranged in a lined state enabling ink jet recording corresponding with the entire width of recording media enables rapid recording execution. Nevertheless, it is extremely important to specify the discharge port (discharge nozzle) having caused discharge defects rapidly to be reflected onto image complementation and ink discharge recovering work.
Technology for solution of such discharge defects is known.
Japanese Patent Application Laid-Open No. H6-079956 describes a recording method, moving image data to be given to an abnormal recording element to image data to be given to another recording element even in an occurrence of abnormality in a recording element and thereby causing the other recording element to complement the record. However, that recording method carries out processing of reading a check pattern discharged onto a detection sheet to detect an abnormal recording element and to superpose image data to be added to that detected recording element onto image data of another recording element. That processing is applicable to a recording apparatus with slow response speed but is hardly applicable to a recording element with fast response speed such as a full-line type recording apparatus.
Moreover, Japanese Patent Application Laid-open No. H2-276647 describes a recording apparatus for detecting a discharge port having caused discharge defects in a line-type recording head to carry out recording with a serial type recording head on a recording position corresponding with the discharge port. However, that discharge defect detection method detects transmitting a heat timing signal to a heat generating resistor member, and detects a signal flowing in the heat generating resistor member at that occasion to detect whether or not the heat resistor member is broken.
Moreover, Japanese Patent Application Laid-Open No. S58-118267 described a recording head as illustrated in FIG. 16. There described is a liquid discharge apparatus provided with a temperature change detecting conductor portion 102 inside a flow channel (inside a nozzle) between adjacent electrothermal energy transducing members 101, including a plurality of nozzles 100 arranged in a row. Moreover, there also described is a liquid discharge apparatus provided with a conductor portion 102 on the rear surface of the side opposite to the surface of a substrate 103 provided with an electrothermal energy transducing member 101 and in a position corresponding with a nozzle 100. However, the case where the conductor portion 102 is provided sideway of the electrothermal energy transducing member 101 is susceptible to influence of heat of the adjacent electrothermal energy transducing member and is susceptible to influence covering thickness of the substrate 103 in the case of providing the conductor portion 102 on the rear surface side of the substrate 103. Therefore, it becomes difficult to precisely detect temperature changes occurring due to repetition of rapid temperature increase and decrease within an extremely short time period.